header{
  display: block;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}
header h1{
  font-family: Arial;
  font-size: 40px;
  font-weight: bold;
}
#newgamebutton{
  display: block;
  margin: 20px auto;
  width: 100px;
  padding: 10px;
  background-color: #8f7a66;
  font-family: Arial;
  color: #fff;
  border-radius: 10px;
  text-decoration: none;
  outline: none;
}
#newgamebutton:hover{
  background-color: #978b77;
}
header p{
  font-family: Arial;
  font-size: 25px;
  margin: 20px auto;
}
#grid-container{
  width: 460px;
  height: 460px;
  padding: 20px;
  margin: 50px auto;
  background-color: #bbada0;
  border-radius: 10px;
  position: relative;
}
.grid-cell{
  width: 100px;
  height: 100px;
  border-radius: 6px;
  background-color: #ccc0b3;
  position: absolute;
}
.number-cell{
  border-radius: 6px;
  font-family: Arial;
  font-weight: bold;
  font-size: 60px;
  line-height: 100px;
  text-align: center;
  position: absolute;
}